Difference between revisions of "Radian"
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A '''radian''' is a unit of measurement for [[angle|angles]]. In a circle, the measure of a [[central angle]] in radians is the ratio of the length of the [[intercepted arc]] to the length of the circle's [[radius]]. | A '''radian''' is a unit of measurement for [[angle|angles]]. In a circle, the measure of a [[central angle]] in radians is the ratio of the length of the [[intercepted arc]] to the length of the circle's [[radius]]. | ||
| − | + | In a unitcircle, a complete angle has measure <math>2\pi</math>, since a complete angle "intercepts" the whole circumference of the circle. Thus, radians can be converted to [[Degree (geometry)|degrees]]: <math>2\pi\; rad=360^\circ\implies\pi \;rad=180^\circ</math>. | |
| + | {{stub}} | ||
[[Category:Geometry]] | [[Category:Geometry]] | ||
| + | [[Category:Definition]] | ||
Latest revision as of 17:30, 10 March 2014
A radian is a unit of measurement for angles. In a circle, the measure of a central angle in radians is the ratio of the length of the intercepted arc to the length of the circle's radius.
In a unitcircle, a complete angle has measure 
, since a complete angle "intercepts" the whole circumference of the circle. Thus, radians can be converted to degrees: 
.
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